This protocol posting deals with objectives & outcome measures of the extension phase up to Month 48. The objective of the extension study is to evaluate the long-term immunogenicity of the HPV 16/18 L1 VLP AS04 vaccine (for all subjects in the HPV Vaccine Group) by enzyme-linked immunosorbent assay (ELISA). The objectives & outcome measures of the primary phase are presented in a separate protocol posting (NCT00196924).